Screw supercharger for vehicle

摘要

A supercharger arrangement for a vehicle engine equipped with a screw supercharger (11). A bypass pipe (21) extends from a main body of the screw supercharger (11) to an upstream intake air pipe (10a) such that part of the intake air compressed to a certain extent in the supercharger returns to an inlet of the supercharger. A duty solenoid valve (22) is connected to the bypass pipe (21) for controlling a flow rate of the air returning to the inlet of the supercharger through the bypass pipe. The screw supercharger is originally designed to match a low speed condition and to feed an excessive amount of air at a high speed condition. The solenoid valve (22) allows the intake air to return to the upstream intake air pipe through the bypass pipe from the supercharger when the engine is operated at a high speed condition so that an excessive amount of air is not supplied to the engine. <IMAGE>